Worst environmental disasters

Deepwater Horizon

An explosion on the Deepwater Horizon in the Gulf of Mexico on April 20, 2010 near New Orleans, Louisiana, killed 11 men. In the 87 days that followed an estimated 4.9 million barrels of crude oil leaked into the gulf.

Credit: U.S. Coast Guard via Getty Images

Chernobyl

Seven million people in the former Soviet republics of Belarus, Russia and Ukraine are estimated to have suffered physical or psychological effects of radiation related to the April 26, 1986, catastrophe, when reactor No. 4 exploded and caught fire. An area half the size of Italy was contaminated, forcing hundreds of thousands of people to be resettled and ruining some of Europe's most fertile agricultural land.

Credit: Zufarov/AFP/Getty Images

Seveso disaster

A dioxin leak from the Icmesa factory near Seveso, a town about 13 miles north of Milan in July, 1976, caused the death of 3,300 animals upon contact with the gas and another 80,000 animals were slaughtered to prevent them from entering the food chain.

Credit: AFP/Getty Images

Union Carbide, Bhopal

A poison gas leak from a pesticides plant in the central Indian city of Bhopal in December, 1984 cost more than 2,850 lives. Pictured here in front of the US Union Carbide factory are victims who lost their sight in the disaster.

Credit: AFP/Getty Images

Three Mile Island

A partial nuclear meltdown inside one of Three Mile Island's reactors, on March 28, 1976, contaminated the surrounding environment with radioiodine and krypton gas.

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The Aral Sea

At one time it was one of the four largest lakes in the world. Now these rusty shipwrecks on the bed of the once great body of salt water stand as markers of an ecological disaster. Diversion of the rivers which fed the lake caused it to dry up, a process that took less than half a century.

Credit: Vyacheslav Oseledko/AFP/Getty Images

Exxon Valdez

When the tanker Exxon Valdez ran aground on March 24, 1989, it would end up spilling 11 million gallons of crude oil into Prince William Sound off Alaska.

Love Canal

Love Canal, a neighborhood in upstate N.Y. was built atop a toxic waste dump. By the late 1970's it was clear that the health risks posed to the residents were grave. A 1979 report by the EPA found a "disturbingly high rate of miscarriages." In addition, the report found "toxic materials in the milk of nursing mothers."

Credit: AP

Tokaimura

An accident at a uranium processing plant in Tokaimura, Japan on September 30, 1999 led to hundreds of residents being exposed to radiation.

Credit: Kyodo News/AP

Fukushima

A massive tsunami in northeast Japan in March, 2011 knocked out emergency generators, required to cool the reactors at the the Fukushima Dai-Ichi nuclear power plant. The plant went into multiple meltdowns over the next three weeks, causing large evacuations and concern about food and water supplies.